Digital motor speed control circuit
US3953776A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1974 |
| Grant date | Apr 27, 1976 |
| Priority date | — |
| Expiry date | Dec 16, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/921
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A tachometer pulse generator is coupled to the shaft of an electric motor. The output of the pulse generator is gated into a pulse counter circuit during a first fixed time interval. During a second fixed time interval which follows the first fixed time interval, the motor is speeded up if the count attained by the counter in the preceeding first time interval is less than a preset number or is slowed down if the count is equal to or greater than the preset number. The first and second time intervals follow each other periodically, thereby alternately measuring the speed of the motor and correcting the same to approach a preset speed which is proportional to the preset number of the counter circuit. Two preset numbers can be employed, one corresponding to a lower speed correction threshold and the other corresponding to an upper speed correction threshold. The motor is speeded up if the count attained by the counter is below the lower speed correction threshold or is slowed down if the count attained by the counter is equal to or above the upper speed correction threshold. No correction is made when the count attained by the counter is equal to the lower threshold number or is betw…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.